Arctic Pearlwort - Sagina nivalis
State Rank Reason (see State Rank above)
Rare in Montana, where it is known from Glacier National Park and the Beartooth Plateau. The remote, high-elevation habitat should greatly minimize the potential for any negative impacts to the viability of the species in the state. Accurate estimates of population levels are lacking.
Arctic Pearlwort is a small, cushion-forming perennial herb with numerous ascending to prostrate stems that are 1-5 cm long and arising from a basal rosette. The linear basal leaves are 5-15 mm long and have pointed tips. Pairs of opposite stem leaves are smaller and united around the stem at their bases. The foliage is glabrous and usually purplish tinged. Small, long-stalked, cup-shaped flowers arise from the axils of the uppermost 1-3 leaf pairs. The 4 purplish, separate sepals are 1-2 mm long, and the 4 white petals are usually slightly shorter. The fruit capsules are 2-3 mm long and expand beyond the appressed sepals.
Flowering in late July-early August.
The more common Sagiona saginoides has 5 sepals that are white- or green- rather than purple-margined. Sagina procumbens does not form small mats. Stellaria and Cerastium have deeply bilobed petals. SPERGULARIA has clusters of secondary leaves in the leaf axils. A hand lens will be needed to distinguish diagnostic characters.
Circumpolar south to Glacier County, MT (Lesica et al. 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).
Observations in Montana Natural Heritage Program Database
Number of Observations:
(Click on the following maps and charts to see full sized version)
Map Help and Descriptions
(Observations spanning multiple months or years are excluded from time charts)
Moist, shaded cliffs in the alpine zone.
Ecological Systems Associated with this Species
- Commonly Associated with these Ecological Systems
Threats or Limiting Factors
STATE THREAT SCORE REASON
Threat impact not assigned because threats are not known (MTNHP Threat Assessment 2021).
- Literature Cited AboveLegend: View Online Publication
- Lesica, P., M.T. Lavin, and P.F. Stickney. 2012. Manual of Montana Vascular Plants. Fort Worth, TX: BRIT Press. viii + 771 p.
- Additional ReferencesLegend: View Online Publication
Do you know of a citation we're missing?
- Lesica, P., K. Lackschewitz, J. Pierce, S. Gregory and M. O'Brien. 1986. Noteworthy collections: Montana. Madrono 33:310-312.
- Lesica, P., M.T. Lavin, and P.F. Stickney. 2022. Manual of Montana Vascular Plants, Second Edition. Fort Worth, TX: BRIT Press. viii + 779 p.